diff --git a/src/codedump.c b/src/codedump.c
index f8de26eec..003a20394 100644
--- a/src/codedump.c
+++ b/src/codedump.c
@@ -510,7 +510,7 @@ codedump(mrb_state *mrb, const mrb_irep *irep)
       print_lv_a(mrb, irep, a);
       break;
     CASE(OP_HASHCAT, B):
-      printf("HASHCAT\tR%d\t\t", a);
+      printf("HASHCAT\tR%d\tR%d\t", a, a+1);
       print_lv_a(mrb, irep, a);
       break;